The 2010 discoveries of Denisovans, the 2012 findings of archaic Afric

The 2010 discoveries of Denisovans, the 2012 findings of archaic African DNA, and the additional 2012 genetic sequencing of Denisovans are part of a longer trajectory dating to the discovery of fossil Neandertals. Ever since the fossil Neandertal discoveries in the 19th century, debates have raged about who they were. Were Neandertals direct ancestors to modern humans? A completely different species? Or a sub-species, like a race? And now what should we do with the Denisovans?

Anthropology can now confidently report that Neandertals, Denisovans, and others labeled archaic are in fact an interbreeding part of the modern human lineage. We are the same species. There has been extensive admixture across modern humans for tens of thousands of years, and at least some admixture across several archaic groups. Neandertals, Denisovans, and other archaics may be the best example of a true human race or sub-species. They are also fully part of the human lineage, with almost all contemporary humans showing genetic admixture with archaics in our genetic signatures.

Still, there have been some problematic aspects to welcoming Neandertals and Denisovans into the human family. Several very wrongheaded interpretations of Denisovans, Neandertals, and archaic admixture have emerged. Because the dominant paradigm has been the replacement hypothesis rather than gene flow across a wide range, contributions from Neandertals and Denisovans are seen as affecting only specific peoples. Since most analyses are carried out in genetic language within a society convinced of genetic determinism, the Neandertal contribution is seen as adding a set of genetic resources other groups do not share.

1. The primary purpose of the passage is to

(A) evaluate the findings of a research -Correct
(B) summarize the history of a research area -The passage doesn't summarise the history
(C) report new research findings -We don't know whether the research is a new research or existing one
(D) reinterpret old research findings -Old research is not talked about here
(E) reconcile conflicting research findings -Passage talks only about 1 research


2. Which of the following,if found true, most clearly strengthens the idea discussed in the second paragraph that Neandertals, Denisovans and humans are the same species?

(A) Neanderthals, Denisovans, and modern humans are all descended from the ancient human Homo heidelbergensis. -Clear answer

(B) By comparing the genomes of apes, Denisovans, Neanderthals, and modern humans, scientists hope to identify DNA segments unique to the different groups. -Hope to identify doesn't strengthen anything

(C) Early results already suggest modern humans underwent genetic changes involved with brain function and nervous system development, including ones involved in language development, after splitting from Neanderthals and Denisovans. -This is a weakener

(D) The scientists found the genetic overlap between the Denisovan genome and that of some present-day east Asians. -This option doesn't talk about Neanderthals

(E) The fact that Denisovans were discovered in Siberia but contributed to the genomes of modern humans living in Southeast Asia suggests the species ranged widely across Asia. -Incorrect

3.Which of the following, if discovered, may help resolve some of the puzzles that the 2010-2012 discoveries raised?

--The puzzle is mentioned in the first passage: "Ever since the fossil Neandertal discoveries in the 19th century, debates have raged about who they were. Were Neandertals direct ancestors to modern humans? A completely different species? Or a sub-species, like a race? And now what should we do with the Denisovans?". So we need an option that helps us tell who Neanderthals and Denisovans were.

A.The common ancestors of Neanderthals and Denisovans spread across Europe and Asia over half a million years ago. -Doesn't answer the question.

B.The new Neanderthal skeletal reconstruction suggests that the interbreeding between Neanderthals and Denisovans occurred at a much earlier period, some 100,000 to 60,000 years ago, before the modern human populations of Europe and East Asia split. -Doesn't answer the question

C.Recently, scientists compared the gene sequences of three human groups – modern Africans, Neanderthals, and Denisovans, and have found that the Neanderthal lineage separated from that of the mysterious Denisovans about 744,000 years ago. -Doesn't answer the question

D.Neanderthals and Denisovans were human populations that separated from the modern lineage early in the Middle Pleistocene. -Correct

E.Extensive DNA sequence data have made it possible to reconstruct human evolutionary history in unprecedented detail. -Doesn't answer the question